Prepare the input
Paste finished prose rather than isolated punctuation. Keep abbreviations, quotes, and line breaks as they will appear, because all can affect segmentation.
Inspect sentence structure locally
Sentence Counter
Estimate sentence boundaries and report words and characters alongside the total, using browser language segmentation where available and no text upload.
- 01Private by designYour text stays in this browser tab.
- 02Bounded and responsiveUp to 500,000 characters in each main text field.
- 03Ready to reuseCopy the result or download a branded TXT file.
Counting and transformations run locally. Nirmion does not send the text in this workspace to an API.
Product guide
Use sentence count as a structural signal
Sentence boundaries are language-sensitive and punctuation-dependent. Nirmion uses Intl.Segmenter when available and a punctuation fallback otherwise, then counts segments containing letters or numbers.Choose the rule
There is no hidden grammar score. The tool estimates sentence units and reports word and character context. It does not label a sentence as correct, complete, active, passive, simple, or complex.
Review the output
Use the total to compare sections, calculate an average manually, or spot an unexpectedly dense block. Review dialogue, bullet lists, initials, decimal numbers, and abbreviations where automated boundaries can differ from editorial intent.
How it works
Browser sentence segmentation with a punctuation fallback
Supported browsers segment the source with sentence granularity and retain only segments containing a Unicode letter or number. The fallback separates on common Western and full-width sentence punctuation or line boundaries. That provides a useful deterministic estimate without claiming a grammar parse or language model analysis.
Useful when
Compare pace and density
Sentence totals are useful when paired with the actual prose and a clear editorial goal.
- Compare an introduction, body, and conclusion to find a section that carries too many ideas in too few sentences.
- Track sentence density across help content, learning material, policy explanations, or product onboarding.
- Preflight a transcript or OCR result for missing punctuation before a human editing pass.
Questions answered
Sentence Counter questions
Practical boundaries matter with text tools. These answers explain what is measured, what is retained, and when a manual review is still needed.
Does a question count as a sentence?
Yes when it forms a detected segment containing letters or numbers. Exclamations and common full-width punctuation are handled similarly.
Why are abbreviations sometimes counted incorrectly?
Boundary detection uses language rules available in the browser, but abbreviations and domain-specific notation remain ambiguous. A fallback based on punctuation is less context-aware, so manual review is necessary.
Does this check grammar?
No. It measures likely sentence boundaries only. It does not diagnose fragments, run-ons, punctuation errors, or writing quality.
Privacy and retention
Your draft stays on your device.
Nirmion performs these operations with browser JavaScript. The workspace does not call the catalogue API with your source text, and completed-job content is kept only in this component memory for re-download.
A downloaded file remains in your browser downloads, device storage, backups, and any location where you share it. Clear or close the page when working on a shared device, and avoid pasting secrets into extensions or third-party clipboard managers.
Tool details
A transparent sentence estimate with supporting counts
Nirmion Sentence Counter evaluates up to 500,000 characters locally and reports likely sentences together with words and grapheme characters. This makes the result useful for structural comparison, readability planning, transcript cleanup, and editorial review without presenting the count as a grammar score.
The downloadable report is text_nirmion_tools_sentence_report.txt. Browser segmentation improves multilingual boundary handling where supported, but abbreviations and unconventional formats can remain ambiguous, so the page documents those limitations clearly.